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l T S Cl LOWE ZSheetsh-Sheeth Improvement in Apparatus for Refining Iron and 'Making steel. No 130380' P atentedl\u,g.\;l. 4l1v9g,w 72.

` y .2 Sheets--Sheet2 T.s.c.LowE.

Improvementin Apparatusfbr Reninglron and.

Making SteeL 7' ParenxedAug.13,1s72.

No.1soao. Il

\ I l QlllllllmlllmlllIfl--IIIIII nulllllllllllllll-nlllllllll la lmll UNITED STATES THADnEUs s. drown, 0E NoEErsTowN, PENNSYLVANIA,

IMPROVEMENT IN APPARATUS FOR REVFINING IRON AND MAKING STEEL.

Speciiication forming part of Letters Patent N o. 130,380, dated August 13, 1872.

Specication describing a Process and an Apparatus for Refining Iron and Making Steel, invented by THADDEUS S. C. LOWE, of Norristown, Montgomery county, Pennsylvania.

My invention consists principally of the manner in which I purify the iron, first, while melting the same; but chiey after it is melted, by extracting from it all or nearly all of the impurities, such as phosphorus, sulphur, excess of carbon, Src., and by afterward recarbonizing the iron to any desired extent, varying from soft or malleable iron to the hardest steel, by a continuous operation in different compartments of the same furnace. My process also enables me while purifying and recarbonizing the iron to save all the gases generated in the charges, and to save the surplus gases for general purposes. My process being applicable to many forms of furnaces, I include in the annexed drawing an inexpensive form of furnace which I consider well adapted to the purpose.

In the annexed drawing, Figure 1 is avertical section of the complete apparatus; Fig. 2,- a horizontal sectional plan of the furnace on the plane of the line w, Fig. 1; Fig. 3, a transverse vertical section of the furnace on the line y of Fig. 2; and Fig. 4, a similar View on the line z of Fig. 2. Fig. 5 is a vertical section of the apparatus (shown in Fig. 1) on au enlarged scale.

4ou, Fig. 1, is a vertical retort, constituting the primary gasgenerator, consisting of a case of cast-iron or other suitable material, b. o is an air-tight vash-pit, across the top of which I arrangea set of grate-bars, d, which are hollow lengthwise and pierced by a number of small holes laterally, as shown. e is a rake, provided with teeth to pass up between nected at their upper ends with the chamberl j, and at their lower` ends with the similar chamber Z. mis an iron pipe coiled around the tubes k. n and o are cylinders of iron, inclosing the coiled pipe m. p is an air-space between said cylinders. q, Figs. 1 and 2, is a retort, of fire-clay or other suitablj; refractory material connected by an iron pipe v,with chamber l. s is a strong air-tight tank containing oil and compressed air. t is a pipe for conveying the oil into the ilue fi. u is a steampipe, connected at one end with the steamvsupply coil fm. by a branch, c, terminating in the .nozzle d3 of the oilpipe t, as shown. The steam-pipe u has another branch, w, which leads down to and connects with the hollows in the grate-bars d. a1 is an air-flue, through which atmospheric air is forced by a fan-blow, er or other suitable device, into the space sur- 'rounding' the series of tubes b1 inclosed in the cylindrical casing c1 and the heads d1 and e. There is a series of holes, f', in the casing c1 for admitting the air into space p. g', Figs. 1l and 2, is an air-space, connected with the space p, as shown. h is an air-flue for admitting hot air into the ash-pit of the generator a.. t" isl an ordinary tubular boiler or Water-heater, having a supply-pipe, j', and a drawing-offhot-water pipe, k', the lower end of which connects with the lower end of coil fm. l is an ordinary damper for regulating the draft. m and n', Figs. 1,2, and 4, compose a furnace in two compartments divided by a vertical partition of masonry, 0, extending from the bottom to near the top arch, as shown f in Fig. 4, the bottom of compartment n being lower. than that of compartment m. p is a flue for carrying off the waste products of combustion. q is a damper for controlling the iue p. o" is an ordinary tap-hole and spout for drawing off the reiined metal in a molten state. s' is a similar tap-hole for drawing the crude liquid metal into the refining compartment n. The tap-hole s is opened and closed by a bar inserted through the hole t', Fig. 2. u', Figs. 1, 2, and 4, is a fire-clay tuyere or pipe closed at its bottom end, and pierced with a number of small holes laterally, as shown, near its bottom. c is an iron tubey or retort for generating gas from liquid hydrocarbons (preferring petroleum.) It is connected at its lower end with.`

the oil-tanks by a tube, zu', as shown in Figs. l and 5. b2 is a steam-pipe, branching from the main steam-pipe u, connected to the tube a2, and provided with an ordinary globe-valve, as shown in Figs. l and 5. c2 is an air-pipe, shown cut off. It is intended to be used for admitting air under pressure into the tube a2.

When it is desired to refine crude or pig-iron, or convert the same into wrought-iron or steel, the crude iron is placed in the melting-compartment m of the furnace, and I introduce into the generator a bituminous coal, coaldust, Wood, sawdust, tan-bark, leather-scraps, peat, straw, wood-shavings, or other carbonaceous combustible solid substances, which are ignited at the bottom where a limited amount of atmospheric air is admitted sulficient to keep up a slow combustion on the grate-bars d. rlhe gases and oleaginous vapors thus generated pass off through the iue into the union-chambery', and down through the vapor-converting tubes la into the chamber l, and thence through the tubes 1^ into the retort g, from which it discharges into the melting-compartment m of the furnace, where it is ignited, the fiame passing into the liuep, back under the retort q, thence into the chimneyspace d2, and up through the tube of the airheater b1, and thence through the tubes ofthe water-heater i', from which the waste products of combustion pass out into the open air, thus heating the retort q, tubes le, casing o,tubes b/ and i. At the same time atmospheric air to support combustion is forced by a blower or other suitable means into tube al, from which it enters the space around tubes b1 in the airheater, passing down which it discharges through the openings f into the space p, between the casings n and o, from which a small portion of this heated air is drawn through the ue h' into the ash-pit of the generator a, for supporting the slow combustion in this generator, the remainder passing through the space c1/,where it is admitted into the meltingcompartment m of the furnace, and is used for supporting combustion therein. While melting the first charge in the compartment m', at the beginning of the operation, I open the damper q', which consists ofdamfire-tile,

open. A part of the flamewpasses over the bridge-wall o to heat the refining-compartment n', preparatory to the introduction into it of the charge of molten metal; and when this compartment has become thus heated the damper q may be pushed into place, closing that part of the flue p. After the retort q, tubes k, and coil m has become heated by thev circulation around them of the hot products of combustion from the furnace m n', I admit water through tube k into the lower end of the coil m, where the same is converted into steam. A small `jet of this is drawn oif through the tube e into the flue i, where it mingles with the gases and oleaginous vapors from the generator a, the mixed vapors and gases passing together into the chamber j, and thence through tub-es k, where the steam is decomposed, forming additional carbonio oxide, and hydrogen,

thus increasing the purity, quantity, and richthrough the small holes at the lower end of the tuyere u', either in a pure state or mixed with atmospheric air, comes in contact with the melted iron, freeing it from carbon, sulphur, phosphorus, and other impurities, and converting it into wrought or soft malleable iron. After the iron has become sufficiently purified, I open the valve in the tube a2, between the petroleum and carbon gas-generator o and the tuyere u", and immediately shut oif the steam and air, and close the valve in the pipes b2 and c2. The pure carbon gas being forced through the molten iron, carbonizes it, and, at the same time, the surplus hydrocarbon-gas unabsorbed by the metal, having a special ainity for sulphur and phosphorus, carries off with it any remaining impurities of that nature. As soon as the iron has become sufficiently carbonized in this way to produce the required quantity of steel (determined by the usual tests) the same may be drawn off and cast into ingots, or used otherwise, as desired.

When steam is used, as above described, for purifying iron, its oxygen, mingling with the carbon contained in the metal, forms carbonio oxide, and this, with the free hydrogen, passes over the bridge-wall o', carrying with them the impurities of the iron, where they come in contact with a hot-air blast, mingling and burning` therewith, and producing an intense heat, which serves, in a great measure, to melt the fresh charge in the compartment m of the furnace. The same is also the case while the operation of recarbonizing the molten iron, as described, is going on. The surplus carbon, or that portion which does not remain in the metal, mingles with sufficient oxygen of the air to keep up an intense heat in both compartments of the furnace.

The oil in the tank s is kept under suicient pressure, by a pump or other suitable means, to force it into the carbon-gas generator t', where it is converted into gas, which is forced, by the pressure in the tank s, through the molten metal in the compartment n of the furnace. There is also sufficient pressure in the steam-coil fm, obtained from the elevation of the water-tank or otherwise, to force the steam through the molten metal; but where air is used an air-pump or other sufficient' machinery is required to compress the air suiiiciently to enable it to force itself through the molten leases :s

metal. When steam is used little, if any, atmospheric air is required to purify the metal.

It will be seen from the arrangement of valves in the steam, air, and carbon-gas pipes that each of these elements can be used separately or mixed in any proportion desired for producing different qualities of metal, and for regulating the heat in the metal.

It will be seen that by the arrangement of the furnace I will not only utilize the gases from the compartment n of the furnace, but I also catch, in the melting-compartment m', all

the particles of iron driven off by the pressure-blasts through the molten metal. In the use of the ordinary converters these particles would be blown out and wasted.

Air alone may be used, if desired, for decarbonizin g and purifying the metal, which afterward may be recarbonized in the manner above described 5 but I prefer to use super- -heated steam, either wholly or in part, for the purpose of purifying the metal.

After the apparatus has been put in operation, and the tubes k and the retort q have become heated, the damper in the ue t' may be closed and the production of gas in the primary generator a stopped; and to supply the necessary gaseous fuel I open the stop-cock inthe pipe t suciently to allow oil from the tank s to be forced into the nozzle a3, Fig. 5, and come in contact with a jetof steam; and from this point the operation is the same as above described.

I claim- 1. The combination of the oil-tank s and retort c', constructed andv arranged and operating in the manner and for the purpose substantially as set forth.

2. The double furnace, composed of two compartments, m anda', cli/vided by a bridgel wall, o', provided with tap-holes s and r', or their equivalents, all constructed and arranged in the manner and for thepurpose substantially as set forth.

3. The combination of the furnace m af, the

vertical tuyere u', tube/@puh branch-tubes 11g/1131;."

and c2, constructed and arragedin the manner and for the purpose substantially as set forth.

4. The introduction of steam, atmospheric air, and carbon-gas together into the molten metal, for purifying and earbonizing purposes, substantially as set forth.

5. The introduction of steam and carbon-gas together into the molten metal, for purifying and carbonizing purposes, substantially as set forth.

6. The combination of the oil-tank s, retort o', pipe a2, and tuyere a', for the introduction V Witnesses:

MILLARD L. WAL'roN, WM. R. WRIGHT. 

